<?php
/**
 * C-01 Website launch checklist.
 *
 * @package ForensixDigital
 */

declare(strict_types=1);

namespace ForensixDigital\Apps\Launch;

defined( 'ABSPATH' ) || exit;

use ForensixDigital\Apps\Content\ContentRules;
use ForensixDigital\Services\Seo\SeoProvider;

/**
 * Turns a handful of facts about the site into a checklist a person can read before going live.
 * The facts are collected in one place and the list is built from them, so the rules can be
 * tested without WordPress. Nothing here changes the site.
 */
final class LaunchChecklist {

	public const DONE    = 'done';
	public const TODO    = 'todo';
	public const UNKNOWN = 'unknown';

	/**
	 * Builds the items.
	 *
	 * @param array<string, mixed> $facts Facts from collect().
	 * @return array<int, array{id: string, title: string, status: string, why: string, link: string, link_label: string}>
	 */
	public static function items( array $facts ): array {
		$settings = $facts['settings_url'] ?? '';
		$flag     = static fn( string $key ): bool => ! empty( $facts[ $key ] );

		$scan_done = 'completed' === ( $facts['scan_status'] ?? '' );
		$serious   = (int) ( $facts['serious_open'] ?? 0 );

		$items = array(
			self::item( 'search_visible', __( 'Search engines are allowed to find the site', 'forensix-digital' ), $flag( 'blog_public' ), __( 'While "Discourage search engines" is on, Google is asked to stay away.', 'forensix-digital' ), (string) ( $facts['reading_url'] ?? '' ), __( 'Open Reading settings', 'forensix-digital' ) ),
			self::item( 'https', __( 'The site uses https', 'forensix-digital' ), $flag( 'https' ), __( 'Browsers warn visitors about sites without https. Ask your host for a certificate and set the site address to https.', 'forensix-digital' ), (string) $settings, __( 'Open General settings', 'forensix-digital' ) ),
			self::item( 'permalinks', __( 'Page addresses are readable', 'forensix-digital' ), $flag( 'pretty_permalinks' ), __( 'Addresses like /?p=123 say nothing to visitors or search engines. Choose "Post name" under Permalinks.', 'forensix-digital' ), (string) ( $facts['permalinks_url'] ?? '' ), __( 'Open Permalink settings', 'forensix-digital' ) ),
			self::item( 'site_title', __( 'The site has its own title and tagline', 'forensix-digital' ), $flag( 'title_set' ) && $flag( 'tagline_set' ), __( 'The title and tagline appear in browser tabs and search results. The WordPress default tagline should be replaced or emptied.', 'forensix-digital' ), (string) $settings, __( 'Open General settings', 'forensix-digital' ) ),
			self::item( 'site_icon', __( 'The site has an icon', 'forensix-digital' ), $flag( 'site_icon' ), __( 'The small icon shows in browser tabs and bookmarks. Sites without one look unfinished.', 'forensix-digital' ), (string) ( $facts['customizer_url'] ?? '' ), __( 'Choose an icon', 'forensix-digital' ) ),
			self::item( 'privacy_page', __( 'A privacy policy page is published', 'forensix-digital' ), $flag( 'privacy_page' ), __( 'Most countries expect one when you collect any data, even through a contact form.', 'forensix-digital' ), (string) ( $facts['privacy_url'] ?? '' ), __( 'Open Privacy settings', 'forensix-digital' ) ),
			self::item( 'sample_content', __( 'The WordPress sample page and post are gone', 'forensix-digital' ), ! $flag( 'sample_content' ), __( '"Hello world!" and "Sample Page" are added to every new site and should not be public.', 'forensix-digital' ), (string) ( $facts['pages_url'] ?? '' ), __( 'Open pages', 'forensix-digital' ) ),
			self::item( 'no_admin_user', __( 'No user is called "admin"', 'forensix-digital' ), ! $flag( 'admin_user' ), __( 'Attackers try the name "admin" first. Create a user with another name, give it the administrator role and delete the old one.', 'forensix-digital' ), (string) ( $facts['users_url'] ?? '' ), __( 'Open users', 'forensix-digital' ) ),
			self::item( 'errors_hidden', __( 'Error messages are not shown to visitors', 'forensix-digital' ), ! $flag( 'debug_visible' ), __( 'Technical messages on a live page confuse visitors and can reveal details about your server. Turn off WP_DEBUG_DISPLAY in wp-config.php.', 'forensix-digital' ), '', '' ),
			self::item( 'sitemap', __( 'A sitemap is available', 'forensix-digital' ), $flag( 'sitemap' ), __( 'A sitemap helps search engines find every page. WordPress provides one unless a plugin switches it off.', 'forensix-digital' ), '', '' ),
			self::item( 'scan_done', __( 'A site scan has been run', 'forensix-digital' ), $scan_done, __( 'The scan checks your pages for broken links, missing titles, images and more.', 'forensix-digital' ), (string) ( $facts['scan_url'] ?? '' ), __( 'Open Overview', 'forensix-digital' ) ),
			array(
				'id'         => 'no_serious_findings',
				'title'      => __( 'No serious problems are open', 'forensix-digital' ),
				'status'     => $scan_done ? ( 0 === $serious ? self::DONE : self::TODO ) : self::UNKNOWN,
				'why'        => $scan_done
					? sprintf(
						/* translators: %d: number of open critical and high findings. */
						_n( '%d critical or high problem is still open.', '%d critical or high problems are still open.', $serious, 'forensix-digital' ),
						$serious
					)
					: __( 'Run a scan first, then this item can tell.', 'forensix-digital' ),
				'link'       => $scan_done && 0 === $serious ? '' : (string) ( $facts['findings_url'] ?? '' ),
				'link_label' => $scan_done && 0 === $serious ? '' : __( 'Open findings', 'forensix-digital' ),
			),
		);

		/**
		 * Filters the launch checklist. Add-ons add items for what they know, for example a backup.
		 *
		 * @param array $items Items: id, title, status (done, todo or unknown), why, link, link_label.
		 */
		$items = apply_filters( 'forensix_launch_items', $items );
		return array_values( array_filter( (array) $items, 'is_array' ) );
	}

	/**
	 * How many items are done.
	 *
	 * @param array<int, array{status: string}> $items Items.
	 */
	public static function done_count( array $items ): int {
		return count( array_filter( $items, static fn( array $item ): bool => self::DONE === $item['status'] ) );
	}

	/**
	 * Reads the facts from WordPress.
	 *
	 * @param string $scan_status Status of the latest scan, empty when there is none.
	 * @param int    $serious     Open critical and high findings.
	 * @return array<string, mixed>
	 */
	public static function collect( string $scan_status, int $serious ): array {
		$sample = get_posts(
			array(
				'post_type'      => array( 'post', 'page' ),
				'post_status'    => 'publish',
				'name__in'       => array( 'hello-world', 'sample-page' ),
				'posts_per_page' => 5,
			)
		);

		$has_sample = false;
		foreach ( $sample as $post ) {
			if ( ContentRules::is_default_post( $post->post_type, $post->post_name, $post->post_title ) ) {
				$has_sample = true;
			}
		}
		$privacy = (int) get_option( 'wp_page_for_privacy_policy' );

		return array(
			'blog_public'       => '0' !== (string) get_option( 'blog_public', '1' ),
			'https'             => str_starts_with( home_url(), 'https://' ),
			'pretty_permalinks' => '' !== (string) get_option( 'permalink_structure' ),
			'title_set'         => '' !== trim( (string) get_option( 'blogname' ) ),
			'tagline_set'       => ContentRules::DEFAULT_TAGLINE !== (string) get_option( 'blogdescription' ),
			'site_icon'         => has_site_icon(),
			'privacy_page'      => $privacy > 0 && 'publish' === get_post_field( 'post_status', $privacy ),
			'sample_content'    => $has_sample,
			'admin_user'        => false !== get_user_by( 'login', 'admin' ),
			'debug_visible'     => defined( 'WP_DEBUG' ) && WP_DEBUG && ( ! defined( 'WP_DEBUG_DISPLAY' ) || WP_DEBUG_DISPLAY ),
			'sitemap'           => self::sitemap_available(),
			'scan_status'       => $scan_status,
			'serious_open'      => $serious,
			'settings_url'      => admin_url( 'options-general.php' ),
			'reading_url'       => admin_url( 'options-reading.php' ),
			'permalinks_url'    => admin_url( 'options-permalink.php' ),
			'customizer_url'    => admin_url( 'customize.php' ),
			'privacy_url'       => admin_url( 'options-privacy.php' ),
			'pages_url'         => admin_url( 'edit.php?post_type=page' ),
			'users_url'         => admin_url( 'users.php' ),
			'scan_url'          => admin_url( 'admin.php?page=forensix-digital' ),
			'findings_url'      => admin_url( 'admin.php?page=forensix-findings' ),
		);
	}

	/**
	 * Whether WordPress or a well-known SEO plugin serves a sitemap.
	 */
	private static function sitemap_available(): bool {
		if ( array() !== ( new SeoProvider() )->detected() ) {
			return true;
		}
		return function_exists( 'wp_sitemaps_get_server' ) && wp_sitemaps_get_server()->sitemaps_enabled();
	}

	/**
	 * One item.
	 *
	 * @param string $id         Id.
	 * @param string $title      Plain sentence that is true when done.
	 * @param bool   $done       Whether it is done.
	 * @param string $why        Why it matters.
	 * @param string $link       Where to fix it, empty for none.
	 * @param string $link_label Link text.
	 * @return array{id: string, title: string, status: string, why: string, link: string, link_label: string}
	 */
	private static function item( string $id, string $title, bool $done, string $why, string $link, string $link_label ): array {
		return array(
			'id'         => $id,
			'title'      => $title,
			'status'     => $done ? self::DONE : self::TODO,
			'why'        => $why,
			'link'       => $done ? '' : $link,
			'link_label' => $done ? '' : $link_label,
		);
	}
}